How Child Support Is Calculated in South Carolina
By Mary Ann Hall, Hall & Means, LLC
If you are filing for child support in Charleston County, the amount the court will order is not pulled from thin air. South Carolina uses a specific formula — the Income Shares Model, codified at SC Code § 63-17-470 and implemented through SC Regulation 114-4710 — that combines both parents’ gross incomes, applies a published schedule, and divides the obligation by each parent’s percentage of that combined income. This guide walks through the actual calculation, including an example with real numbers, so you can estimate your support order before you ever step into the 9th Judicial Circuit’s Family Court.
How South Carolina Calculates Child Support: The Income Shares Model
South Carolina is one of 41 states that uses the Income Shares Model. The premise: children should receive the same proportion of parental income they would have received had the parents remained together. Both parents contribute, and the contribution is proportional to each parent’s share of combined gross income.
The South Carolina Department of Social Services last updated the guidelines on January 15, 2024 — the first update since 2014. That revision raised support amounts to reflect roughly a decade of inflation and raised the combined gross income cap from $30,000 to $40,000 per month. If your support order pre-dates 2024, this matters: the modification threshold (covered below) may already be met simply because the schedule changed.
What Counts as Income Under SC Regulation 114-4720?
“Gross income” for child support purposes is broader than most clients expect. It includes:
- Salaries, wages, commissions, tips, and bonuses
- Self-employment income (gross receipts less ordinary business expenses)
- Rental income (less allowable expenses)
- Royalties, dividends, interest, and capital gains
- Pensions, annuities, severance pay, and Social Security retirement/disability benefits
- Workers’ compensation and unemployment benefits
- Trust income and recurring gifts
Supplemental Security Income (SSI) is specifically excluded. Means-tested public assistance is excluded. And if a parent is voluntarily unemployed or underemployed — meaning they could earn more and have chosen not to — the court can impute “potential income” based on what that parent could reasonably earn given their work history, education, and the local job market.
Which Worksheet Applies to Your Case?
South Carolina uses three worksheets, and the one that applies depends entirely on the custody arrangement:
Most parents filing in Charleston County will use Worksheet A. The shared-custody threshold of 109 overnights — adopted in the 2024 revision — is a sharp line. At 108 overnights, you are on Worksheet A. At 109 or more, you shift to Worksheet C, which applies a 1.5 multiplier to the basic obligation to account for the fact that both households are now bearing duplicate expenses. The math changes meaningfully at that threshold.
An Example: Calculating Support for Two Children
Let’s walk through a Worksheet A calculation. Assume a Mount Pleasant parent filing for support of two children. To keep the math clear, we’ll label the parties as the Custodial Parent (the one the children primarily live with) and the Non-Custodial Parent:
- Custodial Parent’s gross monthly income: $3,000 (working part-time)
- Non-Custodial Parent’s gross monthly income: $5,000
- Combined gross income: $8,000/month
- Number of children: 2
- Work-related childcare paid by Custodial Parent: $400/month
- Custody: Custodial Parent has primary physical custody; Non-Custodial Parent has standard visitation
Step 1 — Look up the basic obligation. The DSS schedule, found at the back of the Child Support Guidelines booklet, shows that at $8,000 combined gross income with two children, the basic monthly obligation is approximately $1,425.
Step 2 — Determine each parent’s income share.
- Custodial Parent: $3,000 ÷ $8,000 = 37.5%
- Non-Custodial Parent: $5,000 ÷ $8,000 = 62.5%
Step 3 — Apportion the basic obligation.
- Custodial Parent’s share: $1,425 × 37.5% = $534
- Non-Custodial Parent’s share: $1,425 × 62.5% = $891
Step 4 — Add work-related childcare and health insurance. The Custodial Parent pays $400/month in work-related childcare. The Non-Custodial Parent owes a 62.5% share of that: $400 × 62.5% = $250. (If the Non-Custodial Parent carries the children on health insurance, that cost would be added to that parent’s side and the Custodial Parent would owe a percentage of the premium.)
Step 5 — Calculate the final support amount. Because the Custodial Parent already keeps the children most nights, that parent’s share is spent directly on the children. The Non-Custodial Parent owes the apportioned base obligation plus a share of childcare:
- Non-Custodial Parent’s base share: $891
- Non-Custodial Parent’s childcare share: $250
- Non-Custodial Parent’s monthly support order: $1,141
That is the guideline amount. The court is presumed to follow it unless one of the deviation factors below justifies a different number.
When Can a Court Deviate From the Guidelines?
The guidelines are rebuttably presumed correct — meaning the court must apply them unless a party shows that applying them would be unjust or inappropriate. SC Regulation 114-4710 enumerates nine categories of deviation factors:
- Educational expenses for the child or for a parent (e.g., private school, tutoring, special-needs schooling)
- Equitable distribution of property in the underlying divorce — if one parent received income-producing assets, that may justify adjustment
- Consumer debts the parties incurred for the family’s benefit
- Families with six or more children — the schedule does not extend that far, so a custom calculation is required
- Unreimbursed extraordinary medical expenses for either parent or the child
- Mandatory retirement deductions (e.g., for a teacher, police officer, or military service member) that reduce real available income
- Support obligations for other dependents — children from a prior relationship for whom a parent is already paying support
- Substantial income from the child (rare; applies mostly to child actors or trust beneficiaries)
- Significant disparity in parental income creating an unjust result
If the court deviates, the judge must make written findings stating the guideline amount, the actual amount ordered, and the factual basis for the deviation. Without those findings, the deviation is reversible on appeal.
Modifying an Existing Support Order
Support orders are not permanent. They can be modified when circumstances change meaningfully after the order is entered.
Substantial Change in Circumstances
South Carolina recognizes the modification of an existing support order when there has been a substantial change in circumstances since the order was entered. A modest dollar swing — for example, a $50/month difference under recalculation — generally will not justify modification on its own. The guidelines schedule was revised in January 2024, and that schedule change, combined with other meaningful changes, is the kind of factor a court will weigh.
Examples of changes that typically support a modification in Charleston practice include:
- A 20% or greater change in either parent’s income (job loss, promotion, business sale)
- The child developing a medical condition requiring ongoing care
- A change in the custody arrangement (the children moving primarily to the other household, or a shift across the 109-overnight line)
- One parent remarrying and the new household altering effective resources
- A child aging out of childcare (eliminating the add-on)
Modifications are not retroactive. The new amount applies from the date the petition is filed, not the date the change occurred — which is why filing promptly when circumstances change is important.
What to Bring to Your Support Hearing
Charleston County Family Court hears support matters with the documentation in front of the judge. To support a calculation under Worksheet A, expect to provide:
- The most recent three months of pay stubs for both parents (if available)
- Last two years of federal tax returns including W-2s and 1099s
- Documentation of work-related childcare expenses — invoices, daycare contracts, or after-school program receipts
- The cost of the child’s portion of health insurance premiums (the marginal cost of adding the child, not the entire family premium)
- Records of any extraordinary medical expenses not covered by insurance
- If self-employed: profit and loss statements, business tax returns, and bank statements
- A completed Financial Declaration (Form SCCA/430), required in every Family Court support proceeding
Bring originals plus three copies — one for the judge, one for opposing counsel, and one for your own record.
How South Carolina Enforces Child Support
Once entered, a support order can be enforced through several mechanisms:
- Income withholding — virtually all SC support orders include automatic wage withholding from the paying parent’s employer
- Tax refund interception — federal and state refunds can be intercepted for past-due support
- License suspension — driver’s, professional, and recreational licenses can be suspended for non-payment
- Contempt of court — willful non-payment can result in jail time
- Credit reporting — arrears over $1,000 are reported to credit bureaus
If you are not receiving the support you have been ordered, the SC Department of Social Services Child Support Services Division can assist with enforcement at no cost.
Frequently Asked Questions
Does South Carolina favor mothers in child support cases?
No. South Carolina applies the Income Shares Model identically regardless of which parent has primary custody. The custodial parent receives support; that parent may be the mother or the father. The guidelines themselves are gender-neutral. For more on how SC custody law works in practice, see our guide on Understanding Child Custody Rights in South Carolina.
What if the other parent is hiding income?
This is common, particularly with self-employed parents. The remedies include subpoenaing bank records, tax returns, and business books; deposing the parent under oath; and asking the court to impute income at the parent’s earning capacity rather than their reported income. The court can also order forensic accounting in higher-asset cases.
Can we agree to a support amount that differs from the guidelines?
Yes, but the court must approve it. Parents can agree to deviate, but the judge will only sign the order if the agreed amount is reasonable and the deviation is supported by one of the enumerated factors. Agreements to pay less than the guideline amount receive particularly close scrutiny because the support belongs to the child, not the receiving parent — it cannot simply be waived.
How long does child support last in South Carolina?
Support generally continues until the child turns 18 or graduates from high school, whichever is later (but not beyond age 19). Support can extend longer for a child with a disability that prevents self-support, and parents can voluntarily agree to fund college expenses, though courts cannot order it absent that agreement.
What happens to support if I become the emergency custodian?
An emergency custody order can change which parent receives support, and the existing support order should be modified accordingly. The same Family Court that issued the emergency order can address support at the temporary hearing that follows. For details on the emergency custody process, see our guide on Protecting Your Children: Emergency Custody Orders in Charleston.
Need help calculating or modifying child support in Charleston? Call Hall & Means, LLC at (843) 377-1341 to schedule a confidential consultation. We will run the worksheet with your actual numbers and walk you through what to expect.
Hall & Means, LLC represents clients throughout the Tri-County Lowcountry — Charleston, Berkeley, and Dorchester counties, served by the 9th and 1st Judicial Circuits — and on a case-by-case basis in surrounding counties. The legal framework discussed here applies statewide in South Carolina.
About the Author
Mary Ann Hall is a founding attorney at Hall & Means, LLC and one of Charleston’s most experienced family law advocates. She is licensed to practice in South Carolina and has built her career advocating for clients and their rights in divorce, custody, alimony, and family law proceedings throughout the Lowcountry.